package com.j2eefast.common.core.utils;

import java.security.MessageDigest;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;


public class Md5Util {

	private static final Logger 					LOG 					= LoggerFactory.getLogger(Md5Util.class);

    private static byte[] md5(String s){
        MessageDigest algorithm;
        try{
            algorithm = MessageDigest.getInstance("MD5");
            algorithm.reset();
            algorithm.update(s.getBytes("UTF-8"));
            byte[] messageDigest = algorithm.digest();
            return messageDigest;
        }
        catch (Exception e){
        	LOG.error("MD5 Error...", e);
        }
        return null;
    }

    private static final String toHex(byte hash[]){
        if (hash == null){
            return null;
        }
        StringBuffer buf = new StringBuffer(hash.length * 2);
        int i;

        for (i = 0; i < hash.length; i++){
            if ((hash[i] & 0xff) < 0x10){
                buf.append("0");
            }
            buf.append(Long.toString(hash[i] & 0xff, 16));
        }
        return buf.toString();
    }

    public static String hash(String s){
        try{
            return new String(toHex(md5(s)).getBytes("UTF-8"), "UTF-8");
        }
        catch (Exception e){
        	LOG.error("not supported charset...{}", e);
            return s;
        }
    }
}
